Oh, I'm so sorry that your excitement just got flattened!! I would love to SEE the problem so everyone can offer some ideas for a solution to salvage the project. We have all had that one quilt (or more) that was so perfect until 'the horror' happened and we had to change plans in some way. But there is usually something that can be done that will make the project livable, if not lovable. So, post a picture or two so we can offer our help.
Having said all that, I threw out the 1st quilt I ever attempted because after getting it half done, I hated the way it was coming out. But, I've never had to do that again. Lesson learned! That was 40 years ago and I don't know how many quilts since.